After a furious flurry between women’s bantamweight champion Ronda Rousey and challenger Sara McMann in the main event at UFC 170, Rousey delivered a lethal knee to the body that dropped McMann and caused the fight to be stopped at 1:06 of the first round Saturday at Mandalay Bay Events Center.

As referee Herb Dean stepped in to stop the fight, McMann appeared to be rising to her feet. Fans booed lustily upon seeing the replay.

While Rousey’s post-fight interview was inaudible because of the booing, McMann was gracious in defeat.

“I had hoped to get back up, but it’s my fault,” she said. “He sees us drop, he’s got to protect us. I should have got up quicker.”

The TKO victory is the first of Rousey’s career. All of her previous fights have ended via armbar submission.

Rousey (9-0) was also taking this fight just 56 days — tying a UFC record for quickest turnaround for a title defense — after defeating Miesha Tate in three rounds at UFC 168.

This was seen as a tough matchup between two Olympic medalists and the most challenging fight of Rousey’s career.

After they traded punches in the middle of the cage, Rousey was the aggressor, moving forward and pushing McMann against the fence. Seconds later while in a clinch, a standing elbow from Rousey rocked the 2004 freestyle wrestling silver medalist.

As they jockeyed for control, Rousey managed to get McMann’s right arm over her head, exposing her side. Rousey landed a perfectly placed left knee that crumpled McMann (7-1) and stopped the fight.

“No matter how hard you train, you’re not going to get your liver stronger,” McMann said.

Rousey, the 2008 Olympic judo bronze medalist, has now won all three of her UFC fights in just one year.